This research proposal U10-CA-12027, is seeking continuation of funding both for the NSABP Headquarters and for non-grant funded institutional members. It has provided support for NSABP breast and colorectal clinical trials since 1972 and 1977 respectively. The long-term goal of those studies continues to be the improvement of survival of patients with these cancers through the use of more effective treatment strategies. Major specific aims for the next five years include: (1) complete accrual in on-going trials B-18, B- 20, B-21, B-23, B-24, R-02 and C-05; (2) continue follow-up in all trials initiated since 1971 that have completed accrual; (3) implement new studies upon completion of on-going trials; (4) maintain quality-control procedures to ensure the integrity of treatment data and validity of therapeutic results; (5) perform data analyses for monitoring accruing protocols and for determining treatment failure and survival of completed studies and; (6) to address treatment-related scientific issues that are adjunctive to the primary research objectives. The latter (number 6) includes: (a) correlating pathologic parameters with natural history and treatment outcome; (b) assessing tumor cell kinetics as discriminants of response and outcome following adjuvant therapy; (c) evaluating other biological markers of potential value for designating populations requiring therapy; and (d) conducting quality-of-life evaluations as they relate to treatment outcomes. To achieve these goals, the NSABP utilizes procedures in all studies which include: (1) eligibility check at randomization; (2) centralized review of pathology materials; (3) on-going toxicity monitoring to ensure identification and prevention of potential problems; (4) verification and editing of coded data with built-in quality assurance mechanisms; (5) employment of mechanisms that minimize delinquent data submission and ensure long-term follow-up reporting; (6) medical audits of active NSABP institutions at least once each three years; (7) reviews of institutional performance with respect to compliance with protocol and data requirements; (8) maintenance of appropriate administrative and fiscal records for institutions supported by subcontract; and (9) presentation of status of all studies at NSABP group meetings and publication of results.